The invention relates to pipe joints or couplings, but more particularly the invention relates to a snap fit connecting coupling with an O-ring type packing.
Quick connect couplings are supplanting other types of fluid couplings such as flared, beaded, and tapered fittings coupled together with a swivel type nut; or hoses that are coupled to a pipe end portion with an external hose clamp. Quick connect couplings are being used in many applications, such as automotive applications, because of a mimimum amount of time they require to make a connection and effect a fluid seal. Such couplings may have an O-ring type packing disposed in the bore of a housing as a means for effecting a seal between the housing and a male end pipe portion; a snap fit connection may be used for quickly connecting the housing to a male end pipe portion. Examples of quick connecting couplings using at least one O-ring between a male end pipe portion and a housing member appear in U.S. Pat. Nos. 4,423,892; 4,541,658; U.K. patent application No. 2,166,509; and European patent application No. 168,223. In such couplings, the O-rings effect a fluid pressure augmented seal along (1) a circumferential length at the O.D. of a male end pipe portion and (2) along a circumferential length at an I.D. portion of a housing (i.e., along I.D. and O.D. portions of the O-ring, respectively). In some applications, redundant O-rings with back-up rings are used because the fluid pressure activated seals are required to effect sealing along the cumulative length at the O.D. of a pipe end portion and the O.D. of a housing portion; redundant O-rings have proven effective when there is relative motion between a coupling housing and an attached pipe end portion. Some couplings such as disclosed in the U.S. Pat. No. 4,541,658 require elaborately shaped, snap fit retaining means for interfitting with a coupling housing and a male end pipe portion being retained.